- This topic has 4 replies, 3 voices, and was last updated 3 years ago by Oliver Shaw.
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10/12/2021 at 4:53 pm #22942KennyJackParticipant
If I apply loads of kicker my shrouds become loose is this normal, and if not what’s wrong?( 450lbs rig tension)
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10/12/2021 at 8:43 pm #22943ChrisParticipant
Well:
when you apply the kicker the thrust will push the boom forwards, which will bend the mast and reduce the distance between the hounds and chainplates. The mast being forced into the gate won’t help this (400lbs gate open is different to gate closed)
So, yes, applying a lot of kicker will reduce the rig tension. If you are actually seeing slack shrouds I would have to question why you’re using so much kicker? If you are seeing a wobbly leeward shroud when sitting out this is normal. any more than that and something is wrong.
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11/12/2021 at 9:47 am #22944Oliver ShawModerator
Thinking about this from a physicist’s perspective, is the front face of the mast still in free air in the slot, and thus free to move further forward, or is it butting up against either the front of the slot or a chock?
If the front face is still free to move forward then the kicker should have no effect on rig tension; the forces are all internal to the mast/boom/sail/kicker system, and the position of the hounds does not alter, and so the tension on the shrouds should not alter.
However it the front of the mast is prevented from moving any further forward the effect of high kicker loads must be to pull the hounds aft; which will increase the tension in the genoa luff and reduce the tension in the shrouds.
But I concur that if your shrouds are visibly loose, other than the leeward one being a little slack when driving hard to windward, then either there is something very odd going on or you are perhaps using excessive kicker.
Oliver
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11/12/2021 at 11:53 am #22945KennyJackParticipant
Thanks for the reply Oliver. The boat I am working on is very old sail No 13050 and I have a newer boat 14211 , the new boat is chocked the old one has no chock and has no mast step conversion I do not have the same problem with the new boat. I love sailing the old boat usually single handed, thus the excess kicker when it blows a bit. I will for next season fit your excellent reefing system and reduce my kicker use. Am I mad to prefer the old boat people think that I am, I always finish towards the back of the fleet but with a huge smile om my face I just love the boat
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11/12/2021 at 12:16 pm #22946Oliver ShawModerator
I do wonder whether on your older boat, with that much rig tension, and no mast steep conversion, you are straining the hull by unduly depressing the mast step. If so, you could be heading for structural problems; metaphorically pushing the mast out through the bottom of the boat.
That much rig tension – on its own – will be generating somewhere around half a ton force downwards on the mast step, before the wind loading even starts! The boat was designed in 1949, long before such high rig tensions became usual, so it was never designed for these loads.
It might be wise to settle for slightly less rig tension!
As for liking your older boat; if she is a bit special for you, and especially if she is a wooden one, go for it!
Oliver
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